At a glance
If you have a mosaic embryo from a previous cycle, Thai IVF labs may offer retesting or alternative options. Learn how mosaic embryos are classified, what retesting involves, and questions to ask your clinic.
Understanding Mosaic Embryos and PGT-A
Preimplantation Genetic Testing for Aneuploidy (PGT-A) screens embryos for chromosomal abnormalities. A mosaic embryo contains a mix of normal and abnormal cells. The degree of mosaicism (low, medium, high) influences how the embryo is classified and whether it may be considered for transfer.
If you have a mosaic embryo from a previous cycle, you may wonder whether Thai clinics can retest it or offer alternative options. This article explains how Thai labs typically handle mosaic embryos and what steps you can take.
How Thai Labs Classify Mosaic Embryos
Thai IVF laboratories generally follow international guidelines for mosaicism classification. Mosaic embryos are often categorized as:
- Low-level mosaicism (20-40% abnormal cells)
- Medium-level mosaicism (40-60% abnormal cells)
- High-level mosaicism (60-80% abnormal cells)
Classification may vary by lab, so it is important to ask your clinic about their specific criteria. Some labs may also use terms like “aneuploid” or “euploid” with a mosaic comment.
Retesting Options for Mosaic Embryos
Retesting a mosaic embryo is possible in some cases, but it depends on the embryo’s quality and the lab’s protocols. Options may include:
- Thaw and re-biopsy: The embryo is thawed, a new cell sample is taken, and PGT-A is repeated. This carries risks of damage to the embryo.
- Transfer without retesting: Some clinics may offer transfer of low-level mosaic embryos after counseling, as they can sometimes result in healthy pregnancies.
- Additional testing: Some labs may offer extended culture or other techniques to clarify mosaicism, but availability varies.
Not all Thai clinics offer retesting for mosaic embryos. Confirm directly with the clinic whether they perform re-biopsy and what their success rates are for thawed embryos.
Questions to Ask Your Thai Clinic
Before deciding on retesting or transfer, consider asking the following questions:
- What is your lab’s classification system for mosaic embryos?
- Do you offer re-biopsy and retesting for mosaic embryos? If so, what is the survival rate after thaw?
- What are your criteria for considering a mosaic embryo for transfer?
- Do you provide genetic counseling to discuss the risks and outcomes of mosaic embryo transfer?
- Can you coordinate with my previous clinic to obtain the original biopsy sample or results?
Alternatives to Retesting
If retesting is not possible or not recommended, alternatives may include:
- Starting a new cycle: Creating new embryos and testing them with PGT-A may yield euploid embryos for transfer.
- Using donor embryos: Some patients opt for donated embryos that have been tested and confirmed euploid.
- Transferring the mosaic embryo: After thorough counseling, some patients choose to transfer a low-level mosaic embryo, understanding the potential risks.
Each option has its own considerations. Discuss with your fertility specialist and genetic counselor to determine the best path for your situation.
Key Takeaways
- Thai labs classify mosaic embryos based on the percentage of abnormal cells, but criteria may differ.
- Retesting via re-biopsy is possible in some clinics but carries risks and is not universally offered.
- Transfer of low-level mosaic embryos may be an option after genetic counseling.
- Always confirm specific lab protocols, success rates, and costs directly with the clinic.
For more general information on PGT in Thailand, see our PGT in Thailand guide and other guides. For common questions, visit our FAQ page.
Frequently asked questions
Can a mosaic embryo be retested in Thailand?
Some Thai clinics may offer retesting of mosaic embryos through thawing and re-biopsy, but this is not standard practice. The embryo must survive the thaw, and the lab must have protocols for re-biopsy. Confirm directly with the clinic whether they offer this service and what the associated risks are.
What is the success rate of transferring a mosaic embryo?
Success rates for mosaic embryo transfer vary widely and depend on the level of mosaicism, the embryo's quality, and the patient's age. Some low-level mosaic embryos can result in healthy live births, but there is an increased risk of miscarriage or chromosomal abnormalities. Genetic counseling is essential before making a decision.
Do Thai clinics accept mosaic embryos from overseas?
Many Thai clinics accept embryos shipped from overseas, including mosaic embryos. However, they will need to review the embryo's genetic report and may have specific criteria for acceptance. Contact the clinic to discuss logistics, legal requirements, and shipping procedures.
Is PGT-A mandatory for all IVF cycles in Thailand?
No, PGT-A is optional and not required for all IVF cycles. It is typically recommended for patients of advanced maternal age, those with recurrent pregnancy loss, or those with a history of chromosomal abnormalities. Discuss with your doctor whether PGT-A is appropriate for your situation.
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Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.
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